public double GetCompressionFlangeLocalBucklingCapacity()
{
// compactness criteria is selected by the most slender flange
double Mn = 0;
ShapeCompactness.IShapeMember compactnessTop = new ShapeCompactness.IShapeMember(Section, IsRolledMember, FlexuralCompressionFiberPosition.Top);
CompactnessClassFlexure flangeCompactnessTop = compactnessTop.GetFlangeCompactnessFlexure();
ShapeCompactness.IShapeMember compactnessBot= new ShapeCompactness.IShapeMember(Section, IsRolledMember, FlexuralCompressionFiberPosition.Top);
CompactnessClassFlexure flangeCompactnessBot= compactnessTop.GetFlangeCompactnessFlexure();
double lambda = 0.0;
double lambdaTop = compactnessTop.GetCompressionFlangeLambda();
double lambdaBot = compactnessBot.GetCompressionFlangeLambda();
CompactnessClassFlexure flangeCompactness;
ShapeCompactness.IShapeMember compactness;
double b = 0;
double tf = 0.0;
if (lambdaTop>lambdaBot)
{
compactness = compactnessTop;
flangeCompactness = flangeCompactnessTop;
lambda = lambdaTop;
b = GetBfTop();
tf = Get_tfTop();
}
else
{
compactness = compactnessBot;
flangeCompactness = flangeCompactnessBot;
lambda = lambdaBot;
b = GetBfBottom();
tf = Get_tfBottom();
}
double Mp = Zy * Fy;
double lambdapf = compactness.GetFlangeLambda_p( StressType.Flexure);
double lambdarf = compactness.GetFlangeLambda_r(StressType.Flexure);
switch (flangeCompactness)
{
case CompactnessClassFlexure.Compact:
Mn = double.PositiveInfinity;
break;
case CompactnessClassFlexure.Noncompact:
Mn = Mp - (Mp - 0.7 * Fy * Sy) * ((lambda - lambdapf) / (lambdarf - lambdapf)); //(F6-2)
break;
case CompactnessClassFlexure.Slender:
double Fcr = 0.69 * E / Math.Pow(b / tf, 2.0); //(F6-4)
Mn = Fcr * Sy; //(F6-3)
break;
}
double phiM_n = 0.9 * Mn;
return phiM_n;
}
public ISteelBeamFlexure GetBeamCase()
{
ISteelBeamFlexure beam = null;
IShapeCompactness compactness = new ShapeCompactness.IShapeMember(section, IsRolledMember, compressionFiberPosition);
CompactnessClassFlexure flangeCompactness = compactness.GetFlangeCompactnessFlexure();
CompactnessClassFlexure webCompactness = compactness.GetWebCompactnessFlexure();
if (flangeCompactness == CompactnessClassFlexure.Compact && webCompactness == CompactnessClassFlexure.Compact)
{
return new BeamIDoublySymmetricCompact(section, IsRolledMember, CalcLog);
}
else
{
if (webCompactness == CompactnessClassFlexure.Compact)
{
return new BeamIDoublySymmetricCompactWebOnly(section, IsRolledMember, CalcLog);
}
else if ( webCompactness == CompactnessClassFlexure.Noncompact)
{
if (flangeCompactness == CompactnessClassFlexure.Compact)
{
return new BeamINoncompactWebCompactFlange(section, IsRolledMember, CalcLog);
}
else
{
return new BeamINoncompactWeb(section, IsRolledMember, CalcLog);
}
}
else //slender web
{
if (flangeCompactness == CompactnessClassFlexure.Compact)
{
return new BeamISlenderWebCompactFlange(section, IsRolledMember, CalcLog);
}
else
{
return new BeamISlenderWeb(section, IsRolledMember, CalcLog);
}
}
}
return beam;
}
//Compression Flange Local Buckling F3.2
public double GetCompressionFlangeLocalBucklingCapacity()
{
double M_n = 0.0;
double phiM_n = 0.0;
ISectionI sectionI = Section as ISectionI;
if (sectionI!=null)
{
ShapeCompactness.IShapeMember compactness = new ShapeCompactness.IShapeMember(Section, IsRolledMember,FlexuralCompressionFiberPosition.Top);
CompactnessClassFlexure cClass = compactness.GetFlangeCompactnessFlexure();
if (cClass== CompactnessClassFlexure.Noncompact || cClass== CompactnessClassFlexure.Slender)
{
double lambda = this.GetLambdaCompressionFlange(FlexuralCompressionFiberPosition.Top);
double lambdapf = this.GetLambdapf(FlexuralCompressionFiberPosition.Top);
double lambdarf = this.GetLambdarf(FlexuralCompressionFiberPosition.Top);
//note: section is doubly symmetric so top flange is taken
double Sx = this.Section.Shape.S_xTop;
double Fy = this.Section.Material.YieldStress;
double E = this.Section.Material.ModulusOfElasticity;
//double Zx = Section.SectionBase.Z_x;
if (cClass== CompactnessClassFlexure.Noncompact)
{
double Mp = this.GetMajorNominalPlasticMoment();
M_n = Mp - (Mp - 0.7 * Fy * Sx) * ((lambda - lambdapf) / (lambdarf - lambdapf)); //(F3-1)
}
else
{
double kc = this.Getkc();
M_n = 0.9 * E * kc * Sx / Math.Pow(lambda, 2); //(F3-2)
}
}
else
{
}
if (cClass == CompactnessClassFlexure.Compact)
{
throw new LimitStateNotApplicableException("Flange local buckling");
}
}
phiM_n = 0.9 * M_n;
return phiM_n;
}
//Compression Flange Local Buckling F4.3
public double GetCompressionFlangeLocalBucklingCapacity(FlexuralCompressionFiberPosition compressionFiberPosition)
{
double Mn = 0.0;
double bf = GetCompressionFlangeWidthbfc(compressionFiberPosition);
double tf = GetCompressionFlangeThicknesstfc(compressionFiberPosition);
ShapeCompactness.IShapeMember compactness = new ShapeCompactness.IShapeMember(Section, IsRolledMember, compressionFiberPosition);
CompactnessClassFlexure flangeCompactness = compactness.GetFlangeCompactnessFlexure();
double lambda = compactness.GetCompressionFlangeLambda();
double Sxc = GetSectionModulusCompressionSxc(compressionFiberPosition);
switch (flangeCompactness)
{
case CompactnessClassFlexure.Compact:
throw new LimitStateNotApplicableException("Compression Flange Local buckling");
case CompactnessClassFlexure.Noncompact:
double Rpc = GetRpc(compressionFiberPosition);
double Myc = GetCompressionFiberYieldMomentMyc(compressionFiberPosition);
double lambdapf = compactness.GetFlangeLambda_p(StressType.Flexure);
double lambdarf = compactness.GetFlangeLambda_r(StressType.Flexure);
double FL = GetStressFL(compressionFiberPosition);
Mn = Rpc * Myc - (Rpc * Myc - FL * Sxc) * ((lambda - lambdapf) / (lambdarf - lambdapf)); //(F4-13)
break;
case CompactnessClassFlexure.Slender:
double kc = Getkc();
double E = this.Section.Material.ModulusOfElasticity;
Mn = 0.9 * E * kc * Sxc / Math.Pow(lambda, 2);
break;
}
double phiM_n = 0.9 * Mn;
return phiM_n;
}